Multifrequency tuning system



Dec. 24, 1935. W. l'. CARPENTER 2,025,645

MULTIFREQUENCY TUNING SYSTEM Filed Oct. 30, 1934 10 Sheets-Sheet lINJULAI-ION g grvuvvvkyt/ 71 638 Zerl. Carfenir X-V MWZ Dec. 24, 1935.w. l. CARPENTE 2,025,645

MULTIFREQUENCY TUNING SYSTEM Filed Oct. 30, 1954 10 Sheets-Sheet 2 I89!] as; 155 151 9e WVeZJ i er 1; Ca 17 19242 81- 1935- V W. H.CARPENTER 5,

HULTIFREQUENCY TUNING SYSTEM Filed Oct. 30, 1934 t 10 Sheets-Sheet 3 nnnnnnn ggnnfi n e 7:5 70 5 4 I I 11 70 Dec. 24, 1935. w CARPENTER2,025,645

MULTIFREQUENCY V TUNING SYSTEM Filed Oct. 30,. 1934 10 Sheets-Sheet 4Dec. 24, 1935.

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MULTIFREQUENCY TUNING SYSTEM Filed Oct. 50, 1954 1o Sheets-Sheet 5 Wsfew I. Garanenfir Dec. 24, 1935. w l. CARPENTER 2,025,645

MULTIFREQUENCY TUNING SYSTEM Filed obt. 30, 1954 10 Sheets-Sheet 6 g 110E 100 E f :80 g #57 :E 66 12 37/ g g hlxsi'erli Car zenfifi Sum/Mm 1 DEQ3 w. l. CARPENTER MULTIFREQUENCY TUNING SYSTEM Filed Oct. 30, 1934 t 10Sheets-Sheet 7 Dec. 24, 1935.

w. l. CARPENTER 2,025,645

MULTIFREQUENCY TUNING SYSTEM Filed Oct. 50, 1954 lo Sheets-Sheet 8 3 WuWM u ZisZer'I. Cbrfanir Dec. 24, 1935.

w. 1. CARPENTER 2,025,645

MULTIFREQUENCY TUNING SYSTEM Filed Oct. 50, 1934 10 Sheets-Sheet 9 Dec.24, 1935.

w. l. CARPENTER MULTIFREQUENCY TUNING SYSTEM Filed Oct. 50, 1934 10Sheets-Sheet l0 I I. I I

Patented Dec. 24-, 1935 iJNIiED STATE LPTENT OFFICE MULTIFREQUENCYTUNING SYSTEM Webster 1. Carpenter, Norfolk, Va.

Application October 30, 1934, Serial No. 750,692

18 Claims. ((31. 250- 10) This invention relates to a multi-frequencytuning system, more particularly to a multi-unit all wave variablecondenser having an exceedingly wide range of capacity, sufiicient tocover a wide frequency range, for example the short wave bands inaddition to the regular radio broadcast band and switching means forcontrolling the tuned circuits of radio equipment.

The invention further aims to provide, in a manner as hereinafter setforth, a multi-frequency tuning system for covering various frequencyranges and for the simultaneous control of a multiplicity of similartuned circuits by a minimum of switching devices, requiring but oneswitching action to make operative any number of similar tuned circm'tscovering the same frequency range, but utilizing an additional switchfor control of the oscillator plate circuit in superheterodyne circuitsand utilizing separate switchings for controlling any number of circuitstuning different frequency ranges. The necessary switching iscarried outthrough the use of a multi-unit variable condenser of the rotary typeincluding sets of rotors arranged in staggered relation with respect toeach other. The rotors of the set tuning the same portion of thespectrum bear the same angular relation to each other, each set ofrotors for a higher or lower frequency range being arranged in aprogressively staggered relation, but all rotors covering the same rangebear the same angular relation to each other. The sets of rotors are soarranged about an axis that when the latter is rotated through 360, therotors progress through their espective stators in a direction toproduce an increasing or decreasing frequency range. The switchingdevices are so disposed relative to the sets of rotors and to the axisof the rotors that a leading switching device operates in conjunctionwith its associated circuits and opens at the moment that the set ofrotors of its associated condenser assembly have completed their coursethrough the stators of such assembly and with each following switchingdevice closing the next successive condenser assembly through to itsassociated circuits as the rotors of such successive assembly entertheir respective stators.

A further object of the invention is to provide, in a manner ashereinafter set forth, a multi-unit vari capacity apparatus or amulti-unit condenser having staggered rotor units, with each unit havingautomatic circuit control, making it possible to have one condenser unitand. coil very highly peaked to a part of the wave band, and with themaid QQndenser unit likewise being highly peaked over the nextassignment of wave band thereby providing a condenser that is peaked allthe way from its minimum wave length to its highest wave length therebyproviding for a very strong signal strength and increasing the overallefiiciency of the equipment.

A further object of this invention is to provide, in a manner ashereinafte set a variable condenser of si .-le, practical construction,having a capacity range sufficient to cover any desired frequency hands.This ability is accomplished by the novel arrangement of the parts, andetermination of capacities of the units of the condenser to peak witheach coil, individually, and respectively connected to that particularunit of the condenser.

A further object of the invention resides in provision whereby as theunit rotor gradually enmeshes into the unit stator and finally reachesth point of being totally enmesh d, it

is at that moment, a tomatically thrown out of circuit by means of anautomatic switching device that will be described hereinafter, and thenext unit of the condenser at the sant-e instant, is automaticallythrown into circuit, covering the next wave band; and so on throughoutthe entire wave :2 ride of the condensers.

The condenser assembly is designated to complete a full turn of degrees,over and over again. Starting at zero on the dial, on up to 369 .egrees,than with a slight turn of dial, returns. It is thereby shown that asthe till capacity of the cond nser is reached and assed, itautomatically s back to the minioum capacity To rotate the dial in revorder, the above facts true in reverse order.

With the inulti-unit condenser, in accordance with this invention, eachunit of the condenser is peaked for highest efficiency a the one andonly coil that this unit has to ti 1%, thereby covering that particu rsection of the wave band with the very highest efficiency. Th s fact iscarried out, and is true with each condenser urit, thereby making themulii-unit variable ser a highly eflicient condenser throughout all wavelengths, and at the same time covering many wave hands.

The wave bands to be covered be divided into two or more sections asdesired with a condenser group to tune each band.

A further object of the invention resides in an automatic switchingmeans for cutting in and out ea ch individual group of condenser unitscov- 5, 1 2; the difierent wave bands, and with the condenswitchingmeans so disposed that as the rotor of a unit is turned the switchingmeans associated therewith acts to complete the circuit for this unitjust at the moment that the rotor of the unit is beginning to enmeshinto the stator of the unit. At this time, also the unit of thecondenser preceding the aforesaid unit of the condenser, is thrown outof circuit automatically by its associated switching means. This methodgoes on consecutively with each unit of the condenser being thrown inand out of circuit at the proper time to avoid overlap on the tuningdial at switchings during the turning of the tuning dial.

The present method generally in daily use is to manually change thecoils or else manually operate a switch that cuts out one set of coilsand cuts in another set of coils. In each case the tuning dial had to beturned through its full range to completely cover each set of coils, aschanged. This necessitated a great amount of turning and tuning thedials, and loss of time, etc.

A further object of the invention is to provide for plural adjustmentsin the switching means to simultaneously close and open the variouscircuits at the desired point.

A further object of the invention is to provide rotatable adjustment ofthe switching means about the axis or shaft whereby a circuit may bethrown into operation at an advanced or retarded position so as not tooverlap the band of frequencies just above or below the aforesaid band.

To the above ends essentially, and to others which may hereinafterappear, the invention consists of such parts and such combination ofparts which fall within the scope of the invention as claimed.

In the drawings:

Figures 1 and 1 when taken together, illus-, trate a rear elevation ofthe multi-unit all-wave variable condenser having combined therewith theduplex switching structures,

Figure 2 is a section on line 2Z, Figure 1, upon an enlarged scale,

Figure 3 is a section on line 33, Figure 1,

Figure 4 is a front elevation of one of the duplex switching structures,

Figures 5 and 6 are sectional views upon the lines 55, and E-$,respectively, Figure 1,

Figure 7 is a section upon line 7-4, Figure 2, Figure 8 is a top planview of the duplex switching structure,

Figure 9 is a section upon line 9-9, Figure 1, Figures 10 and 11 aresectional views upon the lines lQ-ie and H-l l, respectively, Figure 1Figure 12 is a top plan view of the tun ng dial, Figure 13 is adiagrammatical view illustrating a superheterodyne circuit with thecondenser units shown schematically and with the switching structures ofthe double-pole type,

Figure 14 is a view similar to Figure 13 with the switches of thesingle-pole type,

Figure 15 is a diagrammatical view of a tuned radio frequency circuitwith respect to twelve condenser units and with the latter shownschematically, and

Figure 16 is a diagrarmnatical view illustrating the circuit arrangementwith respect to the addition of a condenser unit to the number of conbeincreased or decreased. Each unit of a group of condenser units consistsof a gang or plurality of rotor plates and a gang or plurality of statorplates. The units of each group of units are of like capacity. Thecapacity of one group of units is difierent from that of an adjacentgroup of units.

With reference to Figures 1 and 1 the apparatus includes a base I? ofany suitable material and of the desired width and length. Anchored uponthe base ll are spaced pairs of spaced stand.- ards. The standards ofeach pair are of like construction, but oppositely disposed with respectto each other. The standards of one pair are designated 58, it; those ofanother pair at 29, 22; those of another pair at 22, 23 and those of theother pair at 24, 25. Each standard includes an outwardly directedflange means 26 at its bottom and inwardly directed spaced flanges 21 inproximity to the means 26. its upper end is formed with an opening 28having a threaded wall (Figure 7). Extended from one end of the base H,as well as being secured to the flange means 26 of the standard i3, is abracket 29 formed of a vertical and a horizontal arm 36, 3!respectively. The lower end of arm 3% merges into the outer end of arm3|. The upper end of arm is formed with an opening 32 aligning with theopening 28 in the standard it. anchored to the base i? by the hold-fastdevice 33.

The operating shaft of the apparatus is designated 3e and is secured toin a known manner and operated from a well known form of rotatableadjustable dial and drum structure 35. The latter is operated by thewell known means indicated a 35 (Figure 12). The shaft 34 is journaledin the upper ends of and extends from a pair of upstanding spacedstandards 3'1. The latterare anchored to base ii and arranged betweenand spaced from the standards 2!, 22.

The apparatus includes a series of spaced shafts 3B, 39, dd, 4H and '22arranged in endwise alignment. The shafts ts and t! are disposed inendwise alignment with the shaft 36. is termed an outer shaft. The axesof all of the shafts referred to are arranged in parallelism. All of thesaid shafts are coupled together to provide for their rotating in unisonon the adjusting or" the dial and drum structure 35.

The groups of condenser units of the bank are designated as, 25, 26 and5?. The units of the group 6:2 are designated Q3, Q8; those of the group35 at 58, 5%; those of the group at 52, 53; and those of the group l? at56, 55. group includes a gang of spaced rotors and a gang of spacedstators. The rotors of the groups of units e5, 35, 45 and il areindicated at 55, 51, 58

and as respectively. The stators of the groups n of units :35, as, $5and d? are designated 59, Sfi,

5i and 52 respectively. a

That part 63 of each of the standards below the flanges 27 (Figures 3,9, i0 and i1) is of a width corresponding to that of the base ii. Thatpart 63' of each of thestandards above the flanges 2'1, for a portion ofthe length of the standard is of oblong contour and of greater widththan that of the base ii. Each standard has the bottom of its partedformed wit-ha pair of the Each standard at The flange means 25 of thestandards are The shaft 33 Each unit of a 71 flanges 2'? arranged inspaced relation. The 7 part 63 projects from each' side and theflanges2? are arranged adjacent to the sides of base 8?. That part 6% of eachstandard above the part 53' is substantially of triangular contour andit is ill formed at its upper end with a circular extension 65 providedwith the opening 28.

Common to the stators of each group of units is a plate 66 ofinsulation. The gang of stators of one unit of a group is arranged inspaced relation to the gang of stators of the other unit of the group.The gangs of stators of each group of units are positioned upon theplate 66. A pair of combined guide, spacing and holding elements 61 iscarried by plate 66 for the gang of stators of each unit. Spaced bindingposts E58 for circuit connections depend from plate 66 and areelectrically connected with a gang of stators of each unit. As two gangsof stators are mounted on a plate 65, two spaced binding posts 68 areemployed. The plate 853 is positioned against and secured to the lowerfaces of the flanges 2? of a pair of standards. The holdfast means forthe plates (it are indicated at 68', and which in connection with theflanges 27 suspend the plates 66 above and in spaced. relation withrespect to base ll. The stators of each gang are of like form andarranged in paral cl spaced relation. All of the stators are of the sameform. The contour of a stator is shown in Figures 3, 9 and 11.

The shafts 39, 49, 4| and .2 respectively bodily carry therewith a groupof spaced gangs of rotors 44, a group of spaced gangs of rotors 45, agroup of spaced gangs of rotors 46 and a group of spaced gangs of rotors41. The groups of gangs of rotors are arranged about an axis commonthereto. One group of gangs of rotors is arranged an angular distancefrom an adjacent group of gangs of rotors about such axis.

The rotors of each gang are of like form and arranged in parallel spacedrelation. All of the rotors are of the same form. Each rotor includes abody part 69 having extended from one corner thereof a circular hub orextension 748 formed with an opening it for the passage of the shaftwith which it is associated (Figure 10). The body part 69 of each rotoris of what may be termed substantially of semi-pear shape outline, andformed with two edges, one designated it being straight and the otherdesignated 12 being of suitable curvature. The edges ll, '12 at one endmerge into each other and at their other end merge into one side ofextension 10 at spaced points on said side.

The hubs iii of the gangs of rotors 56 of the groups of condenser units44 are mounted upon shaft 39. Carried by the latter is a spacing collar13 for the gangs. Spacing collars 14 are arranged between the hubs iiiof the rotors of each gang. Spacers l5, '56 on shaft 39 are arrangedagainst the hubs is of outer rotors 55 of said gangs. Binding sleevesTi, 18 bear against the spacers l5, 76 respectively. The sleeves 1?, 18are formed with end flanges 2'9, 89 respectively. The sleeves areoppositely disposed, peripherally threaded, extend through and engagewith the walls of the openings 28 at the upper ends of a pair ofstandards. The flanged end 79 of sleeve Tl abuts the outer end of spacer'35. A washer 80 abuts the outer end of spacer l The nonflanged end ofsleeve i3 abuts washer as. A locking nut 81 is carried by sleeve 78.

The hubs if! of the gangs of rotors 5'! are mounted upon and are bodilycarried with the shaft M3. The gangs of rotors 5'! are maintained inspaced relation by a collar 82 positioned in shaft 453. The hubs it ofthe rotors 5'! of each gang are spaced apart by collars 83 interposedtherebetween and carried by shaft 49. The hubs T of the gangs of rotors58 are mounted upon and bodily carried with the shaft 4| The gangs ofrotors 58 are maintained in spaced relation by a collar 83 positioned onshaft 4!. The hubs 75 of the rotors 58 of each gang are spaced apart bycollars 84 interposed therebetween and carried by shaft 4!. The hubs itof the gangs of rotors 59 are mounted upon and bodily carried by theshaft 42. The gangs of rotors 59 are maintained in spaced relation by acollar 85 positioned on shaft 42. The hubs T0 of the rotors 59 of eachgang are spaced apart by collars 85 interposed therebetween and carriedby shaft 42. There is associated with each group of condenser units 25,

46 and 41 a pair of spacing collars which are arranged in the samemanner, are of the same form as that of the collars Z5 and i5 and bearthe same reference characters. There is associated with each group ofcondenser units 5, 4E and ii a pair of binding sleeves and a lock nutwhich are arranged in the same manner, are of the same form as that ofthe sleeves 7?, l3 and lock nut 8i and bear the same referencecharacters.

A spacer H, a spacer a sleeve H, a sleeve l5 and a washer 88, inconnection with the other collars of each group of condenser units bindthe rotors of the latter together whereby each of the gangs of rotors ofeach group of units will bodily move together with the shaft upon whichthe rotors are connected to. The nuts 8! lock sleeves 78 in theiradjusted positions. The rotors 5t, 57, 58 and 59 bodily move together onthe rotation of the shafts 35, 45, 4! and 42 from shaft 34.

The shafts 3Q, 46, 4S and 42 are journaled in and extend from each ofthe sleeves l1 and i8. The shaft 39 is coupled to shaft 40. The shaft iscoupled to shaft 42. The shafts 45 and 4! are coupled to the operatingshaft 34. The shaft 38 is coupled to shaft 39. The coupling meansbetween shafts 33, 39; between shafts 39 and 4%; between shafts 34, Mand between shafts GI and 32, are of the same construction and formelements of a switching structure.

There is associated with the groups of conenser units 44, 45, and i! thecontrolling switching structures Si, 83, 88 and 953 respectivelytherefor. The switching structures are of like form and the descriptionof one will apply to the others. With reference to Figures 2 and 4 to 8,each switching structure includes a hanger 9! formed of a pair ofupstanding forwardly inclined arms 92, 93, provided in proximity totheir ends with lateral enlargements 94, 95 respectively having openings9%, El respectively, and rearwardly extending lower end portionsrespectively. The openings 33? of the arms 93 have mounted therein theinsulating bushings 91'. The arms 92, 93 have formed integral with thevertical edges of the said lower end portions 98, 93 the forward face ofa vertical plate I98 50 which bridges the space between said arms and isof a length to extend laterally at one end, as at H)! from the outerside of end portion The plate is provided with screw threaded openingsH32, H33, H54 and E55. Formed integral (35 with the outer side face ofthe arm 32 and disposed at right angles thereto is a peripherallythreaded tubular extension having its inner face forming a flushcontinuation of the wall of opening 95. T4)

Opposing in spaced relation the rear face of plate lei? is a pair ofsupports 2%, IS! of substantially inverted T-shape formed with basesH33, 199 respectively and stems Ht.

H i respectively. The base N18 is formed with T5 openings aligning withthe openings I92, I93. The base I 99 is formed with openings aligningwith the openings I34, I95. Extending through the base I98 andthreadedly engaging with the walls of the openings I94, I95 is a pair ofspaced headed binding screws II2. Each binding screw has arrangedthereon a sleeve II2 of insulation which extends to the plate I99. Thesleeve is of less length than the screw. Mounted on the sleeves II2',carried by the screws H3 is an upstanding support II4 (Figure 2) formedat its upper end with a screw threaded opening I I5 which registers witha forwardly directed, interiorly threaded lock nut tubular member I I 6,having extending therethrough and threadedly engaging therewith anadjusting screw II1 for a purpose to be referred to. The screw II1 alsoengages the wall of opening H5. Mounted on the sleeves I I2, carried bythe screws I I2, is an upstanding support H8 (Figure 6) of the same formas the support I I4, Connected to and extending forwardly from supportH8 is a tubular member I I9 of the same form as the member H6. Extendingthrough and threadedly engaging with member H9 is an adjusting screw I29for a purpose to be referred to. The stem III] is formed with a screwthreaded opening I2I with which threadedly engages an adjusting screwI22 for a purpose to be referred to. The screw I22 carries a lock nutI23. The stem III is formed with a screw threaded opening I24 with whichthreadedly engages an adjusting screw I25 for a purpose to be referredto. The screw I25 carries a lock nut I28.

Mounted on the sleeves I I2, carried by the binding screws I I2 is anupstanding normally open circuit closing unit consisting of a set ofresilient brushes I21, I28 and I29 (Figure 6). The brushes I28 and I29are connected together in spaced relation in proximity to their outerends by a coupling piece I 39 of insulation. The brush I28 at its outerend is formed with a contact point I3I which extends towards brush I21.The latter is normally spaced from the point I3I. The brushes I28, I29are moved in unison by a means to be referred to in a direction to bringthe point I3I to engage brush I21 to close the circuit. Mounted on thesleeves I I2 carried by the binding screws II3 is an upstanding normallyopen circuit closing unit consisting of a set of resilient brushes I32,I33 and I34 (Figure 5). The brushes I33 and I34r are connected togetherin spaced relation in proximity to their outer ends by a coupling pieceI35 of insulation. The brush I33 at its outer end is formed with acontact point I 36 which extends toward brush I32. The brushes I33, I34are moved in unison, by a means to be referred to in a direction tobring the point I36 to engage brush I32 to close the circuit.

Mounted on the sleeves H2 carried by the screws H2 and spaced from plateI99 (Figure 6) are the insulators I38. Carried by the sleeves II 2 onthe screws I I2 and interposed between insulators I38 and plates I99 arethe terminals I38. Positioned onthe sleeves II2 carried by the screwsII2 are sets of insulators I39 which are interposed between brushes I21,I28, I29 and supports I I8. Mounted on the sleeves II2 carried by screwsII3 and bearing against plate I99 (Figures 2 and 5) is an insulator I49.Positioned on the sleeves I I2, carried by the screws I I3 are sets ofinsulators I 4| which are interposed between brushes I32, I33, I34 andsupports H4. The insulators I38 and I49 are arranged against I thesupports II8 and II 4 respectively.

The brushes I21, I28 and I29 are extended from the insulators I39 andprovide terminals I42, I43, I44 respectively. The brushes I32'and I33are extended from the insulators MI and provide terminals I45, I49respectively. 5

The brushes I21, I29 are arranged in the path of the adjusting screwsI22, I29 respectively, to be independently adjusted by the latterwhereby the space between point I3! and brush I21 may be varied and thetension of brushes I 21, I29 and I29 may be increased or reduced. Thebrushes I32, I34 are arranged in the path of the adjusting screws I25,II? respectively to be independently adjusted by the latter whereby thespace between point I33 and brush I32 may be varied and the tension ofthe brushes I32, I33 and I34 increased or decreased.

The sets of brushes I21, I28 and I29 of the 7 switching structures 81,B8, 89 and 99 are generally indicated at 81", 88", 39"and 99"respectively. The sets of brushes I32, I 33 and I 34 of the switchingstructures 81, 88, 89 and 99 are generally indicated at 81, 88', 89 and99 respectively.

Each switching structure includes as heretofore described, two sets ofswitching elements or brushes, each set forming a circuit closing unit.The said sets of elements or brushes are operated simultaneously tocircuit closing positions by a device to be referred to. a

Each switching structure includes a device for simultaneously operatingits sets of brushes and the said device also acts as a coupling meansbetween shafts 33, 39 or shafts 39, 49 or shafts 34,

II or shafts II 42. Each of the said devices is of like form and thedescription of one will apply to the others. However, before describingthe construction of such devices it will be pointed out, with referenceto Figures 1 and 1 that the hanger 92 of switching structure 81 issuspended from shafts 38, 39; that of switching structure 88 from shafts39, 49; that of switching structure 89 from shafts 34, 4| and that ofswitching structure 99 from shafts M, 42. The manner in which aswitching structure is suspended is clearly shown in Figure 7. Each ofsaid devices is termed a combined shaft coupling and'switch operatingelement, and consists of a vertically disposed rotatable apertured discI 41 of non-conducting material having anchored to and opposing one sideface thereof the outer ends of a pair of 50 oppositely disposedangle-shaped outwardly directed arms I48, I49 (Figures 7 and 8) mergingat their inner ends in a collar I59 formed with a cam I5I disposedcircumferentially of its outer edge. Anchored to and opposing the otherside face of the disc I41 is a pair of oppositely disposed angle-shapedoutwardly directed arms I52, I53 merging at their inner ends in a collarI54 formed with a cam I55 disposed circumferentially of its outer edge.The cams I5I, I55 are arranged in sidewise parallel spaced relation. Thebrush I29 is positioned in the path of cam I 5i to be shifted by thelatter on the rotation of the disc I41. The brush I34 is positioned inthe path of the cam I55 to be shifted thereby on the rotation of discI41. When the brushes I29, I34 are shifted by cams I5I, I55 theyrespectively close the circuit for a group of condenser units and thecircuit for the oscillator plate. h

The collars I59, I54 of the switching structure 81 0 are fixed to theshafts 38, 39 and couple shafts 38, 39 together whereby the collars, aswell as said shafts, willbe rotated in unison. The collars I59, I54 ofthe switching structure 88 are fixed to the shafts 39', 49 and coupleshafts 39, 49 together whereby the collars of structure 8?, 88 andshafts 38, 39, 40 will be rotated in unison. The collars I59, I54 of theswitching structure 89 are fixed to the shafts 34, 4i and couple shafts34, 4I together whereby the collars of structure 89 as well as theshafts 34, M will be rotated in unison. The collars E56, I54 of theswitching structure 95 are fixed to the shafts H, 42 and couple shaftsti, 62 together whereby the collars of structures 89, Sit and shafts 3AI and 42 will be rotated in unison. To provide for the shafts 34, 38,3?}, 6B, 4! and .2 to rotate in unison, the shaft 34 is coupled to shaftAll, and for such purpose a disc I56 of insulation is interposed inspaced relation between the opposed ends of shafts 34, 40. Secured toand suitably insulated from the opposed ends of the shafts 3 5, 1-8 arecollars I57, 558 respectively. The collar i5? is connected to one sideof disc I56 by a pair of oppositely extending arms $59. The collar I58is secured to the disc I55 by a pair of oppositely extending arms 69.The arms I59, I65! are integral at one end with collars I51, I58respectively and have their other ends anchored to disc E56 by holdfastmeans I6I.

A disc I4? is arranged between and spaced from the opposed ends ofshafts 38, 39; between and spaced from the opposed ends of shafts 39,40; between and spaced from the opposed ends of shafts 3 ii; and betweenand spaced from the opposed ends of shafts M, 42.

Each switching structure is detachably secured in position whereby itmay be removed when desired, and for such purpose its collars use, i aresecured in position by removable set screws I62 and its tubular member I65 extending towards sleeve ll. A member IE5 is mounted on a shaft 39,In), M or 42. Threadeclly engaging with sleeve ii. and member H35(Figure 7) is an interiorly threaded coupling sleeve I53. A look nut itsis carried by member N35.

The shafts S4, 38, 39, 49, 4| and 42 provide a common axis for the hubsiii of the rotors and for the collars H58, 554. The rotors 56, 5?, 58and 59 are arranged in staggered relation with respect to each otherabout said common axis. The cams of said switching structures arearranged in staggered relation about said common axis. The cams of oneswitching structure are arranged a distance of ninety degrees from thecams of an adjacent switching structure and a like arrangement has beenheretofore referred to with respect to the rotors of the said pairs ofcondenser units. It is to be understood that when a greater or smallernumber of groups of condenser units are used than that as shown that thedistance between the rotors of said groups may be changed and theforegoing may also apply to the cams of the switching structures whenthe number of the latter is increased or decreased.

With reference to Figure 13, a superheterodyne circuit arrangement He isset up with respect to nine condenser groups, the ninth being designatedC The other condenser units are designated C C C and C The units C C (3and C are associated with the condenser units C C 0 C respectively. Theassociated units of each pair, or group, have their circuit closedsimultaneously and independently of the other associated units of saidpairs or group, and the unit C The circuit I10 includes a switch I73 forconnecting thru element L the antennae, not shown, to a radio frequencyamplifier A. Simultaneously with the closing of the switch H3,

to element D the switching structure 81 is closed making active circuitsL C and L C The arrangement just referred to is the first position. Asthe shafts revolve into the second position, the switch I13 is connectedto elements D D and D and these latter remain in this position for theremainder of the revolution of the shafts until position oneis againreached. Simultaneously with the changing of switch the units 88' and38" close making operative circuits L O and L C but making circuit L -Cinoperative until position one is again reached. The circuits L C and Ii-C are receptive to a band of frequencies adjacent to the band coveredby L C and L -C but slightly overlap them. As the shafts are furtherrevolved into position three, the switch Hi3 remains as position two andthe units 88' and open and simultaneously with the opening of the latterthe units 83 and 89 close making operative circuits L -C and L Creceptive to a band of frequencies adjacent to the band receptive by thecircuits L C and L -C but slightly overlapping it. Further revolution ofthe shafts makes position four without changing the position of switchI73 whereby the units 89' and 39 open, and simultaneously with theopening of the latter the units 99 and Bil" are closing, makingoperative circuits Il -C and L C covering a band of frequencies adjacentto the band covered by L C and L C Upon further turning of the dial orshafts the switch H3 disconnects from coils D D and D and connects tocircuit L C which is back to first position again with the units 87 and8'1 closed, but units 38 and 88", Bi? and 89 and 9B and 9?) open. Theswitch H3 is necessary to connect the antenna to either radio frequencystage for broadcast band pre-selection or to the mixer direct for shortwave operation.

With reference to Figure 14, a superheterodyne circuit I'M is shownsimilar to circuit I78 except single pole type switches are utilizedinstead of multiple pole switches. Figure 14 is a diagrammatical view ofa circuit arrangement H4 set up with respect to eight condenser unitsemploying single pole switches to control the different circuits. Thecondenser units are C 0 C and C and associated with the said condenserunits are C C C and C respectively. The associated units of each pairhave their circuit controlled simultaneously and independently of theother:

associated units of said group. With units 878l" closed, circuits L -Cand L --C are made operative, and the arrangement just referred to isthe first position. The units 88--88", 898" and 98il" are open in thefirst position. As the shafts are further turned into position two,units 8'I'--8'l open and simultaneously units 88'88" close makingoperative circuits L -C and L C In position two, circuits L -C L C L' CL C L --C and L C are inoperative. As the tuning dial is turned furtherto position three, units 8888" open and simultaneously units 8989 closemaking operative circuits L C and L C but with circuits L -C L -C L C L-C l' r C and L inoperative. As the dial is turned further to positionfour, units 8989" open and simultaneously units lfi9ll" close makingoperative circuits L C and Li -C but with circuits L C L C L C L C L Cand L C inoperative. As the tuning dial is further turned, position oneis reached again with units 8?'8'I closed making operative circuits L Cand With reference to Figure 15 it illustrates a tuned radio frequencycircuit ll with twelve condenser units using multiple pole switchingmeans. The condenser units are C C C and 0*. Associated with C are C andC Associated with C are C and C Associated with C are C and C Associatedwith C are C and C With the closing of switching means 31 circuits L -CL C and L -C are made operative. All of the other remaining circuits areinoperative with the circuits controlled by switching means 88, 89, and95 open. This arrangement just referred to is the first position. Withfurther turning of the tuning dial switching means 3? opens andsimultaneously switching means 83 closes making circuits L C U-C and L Coperative but making circuits L C L --C and L C inoperative. Circuitscontrolled by switching means 89 and 9B are also inoperative during thesecond position. With further turning of the tuning dial switching means88 opens and simultaneously switching means 89 closes making operativecircuits L --C L C'- and L -C which is the third position wherein withthe opening of switching means 88 circuits controlled thereby, namely; L--C L ---C and L C also circuits controlled by switching means 81 and 96are inoperative. With further turning of the tuning dial position fouris reached with the opening of switching means 89 and the simultaneousclosing of switching means 90 making operative circuits L C L C and L Cbut making inoperative circuits L C L' J and L C also circuitscontrolled by switching means 81 and 88 are inoperative in the fourthposition. With further turning of the tuning dial position one isreached again with the opening of switching means 96 and thesimultaneous closing of switching means 81 making operative circuits L CL C and L C but with circuits L -C L C and L -C inoperative, alsocircuits controlled by switching means 88 and 89 remain 'inoperative inposition one.

Figure 16' is a diagrammatical view of a circuit arrangement H9 set upwith respect to nine condenser units, the ninth being designated C Theother condenser units are designated 48, 49, 5t, 5 l, 52, 53, 54 and 55.The units 18, 56, 52 and 5d are associated with the units 49, 5|, 53 and55 respectively. The associated units of each group have their circuitclosed simultaneously and independently of the other associated units ofsaid groups and the group C The circuit H9 includes a switch I forconnecting through element D the antenna, not shown, to the radiofrequency amplifier A. Simultaneously with the closing of the switch588, the units 8'! and 81 are closed making active circuits L C and L CThe arrangement just referred to is the first position. As the shaftsrevolve into the second position, the switch I80 is connected to D D andD and these latter remain in this position for the remainder of therevolution of the shafts until position one is again reached.Simultaneously withthe changing of switch i8i the units 81 and 81" areopened and the units 88' and 88" close making operative circuits L C andL C but making circuit L -C inoperative until position one is againreached. The circuits L C- and L C are receptive to a band offrequencies adjacent to the band covered by circuit L --C and L C butslightly overlap them. As the shafts are further revolved into positionthree, the switch 186 remains as in position two and the units 88 and38" are opened and simultaneously with the opening of the latter theunits 89' and 89" close making operative circuits L -C and L C receptiveto a ban-d of frequencies adjacent to the band receptive by the circuitsL C and L*() 5 but slightly overlapping it. Upon further revolution ofthe shafts makes position four without changing the position of switch53%] whereby the units 88 and 89 open and simultaneously with theopening of the latter, the units 9E and 90! are closed, making operativecircuits L"C and L -C covering a band of frequencies-adjacent to theband covered by circuits L C and L C but slightly overlapping them.Further turning of dial, switch let disconnects from D, D and D '15 andconnects to L -C which is back to first position again with units 83"and 8? closed but units 88, 8B", 89, 89'', 9E! and 953 open.

It will be noted that While the grid inductances of both the mixer andoscillator circuits are simultaneously made either operative orinoperative through the action of one of the circuit closing members ofthe switch devices, elements D D D and D are also controlled through theaction of the other circuit closing members of the switch- 25 es andwhich members are operated simultaneously by virtue of bearing the samephysical and electrical relationship to each other according to theirrelative positions with respect to the shafts.

The true associated control circuit is accom- 3o plished through thefact that one of the circuit closing members of each of the switchesacts in a manner to simultaneously control the circuits of both themixer and oscillator grid inductances. The other circuit closing memberof each of the 35 switches plays no part in the associated controlcircuit, except that they are necessary to make the oscillator circuitoperative. The circuit closing members of each switch operatesimultaneously only because of the fact that the oscillator plateinductance must match its associated grid inductance to make theoscillator circuit operative.

The rotary units employed in connection with the short wave band do nottrail in the same path 4; .on rotation. The rotary units employed inconnection with regular broadcast band do not trail in the same path onrotation.

Each switching structure is formed of a rotatable section and asuspended section. The rotatable section being the parts of thestructure which constitute the coupling means between a pair of shafts,and the suspended section is formed from the hanger 9! and the partscarried by the latter. As the suspended section is 55 connected to apair of shafts by the lock nut I64 such section may be adjustedcircumferentially with respect to the shafts by loosening lock nut i6 3and rotating extension H35 in sleeve 183 to the desired position ofsuspended section and 60 then retighten lock nutlt. The position of thesuspended section of one switching structure with respect to that of anadjacent switching structure is such as to cause the simultaneousclosing of one pair of circuit closing units on the open- 65 ing of anadjacent pair of circuit closing units. Each pair of cams is of a widthto insure the riding of them against the brushes of the circuit closingunits with which they are associated. As shown, the cams are extendedlaterally from the 70 collars.

What I claim is:

1. In a multi-frequency tuning system for covering various frequencyranges, a bank of groups of condenser units, each unit of .agroupinclud- 75 ing ganged rotors and ganged stators, one group of unitstuning the same portion of the spectrum and a portion different fromthat tuned by any of the other groups, a rotatable means common to thegangs of rotors, said gangs of rotors being angularly disposed withrespect to and arranged in staggered relation about said means, thegangs of rotors tuning the same portion of the spectrum bearing the sameangular relation to each other, each higher or lower range tuning groupof units being disposed in a progressively staggered relation, saidgroups of gangs of rotors being so arranged about said rotatable meansthat when the latter is rotated 360 each group of gangs of rotorsprogress through their associated gangs of stators in a direction whichproduces an increasing or decreasing frequency range, a normally openpair of circuit closing units suspended from said rotatable means foreach group of condenser units and arranged adjacent to the latter, and arotatable operating device for each pair of circuit closing units, eachof said devices forming a part of said rotatable means and including apair of spaced elements for simultaneously closing the pair of circuitclosing units with which the de vice is associated, the said spacedelements of said devices being disposed about said rotatable means instaggered relation with respect to each other and corresponding inarrangement to the staggered arrangement of said groups of gangs ofrotors whereby on the operation of said rotatable means the closing ofone pair of circuit closing units will be had on the opening of anadjacent pair of circuit closing units.

2. In a multi-frequency tuning system as set forth in claim 1, thespaced elements of each of the operating devices for the circuit closingunits being in the form of a pair of spaced parallel cams of likeconstruction.

3. In a multi-frequency tuning system as set forth in claim 1, havingthe said rotatable means thereof consisting of a series of alignedshafts, a coupling means between an intermediate pair of said shafts andthe circuit closing units operating devices, the said devices connectingthe other of said shafts together and to the said intermediate shafts.

4. In a multi -frequency tuning system as set forth in claim 1, asupport for said rotatable means, and cor-,ctin means on said rotatablemeans and on the suspension for each pair of circuit closing units fordetachably securing the suspensions to the said rotatable means.

5. In a multi-frequency tuning system as set forth in claim 1, the saidrotatable means being formed from a series of aligned shafts, a couplingmeans between an intermediate pair of said shafts and the circuitclosing units operating devices, said devices connecting the other'ofsaid shafts together and to the said intermediate shafts, said devicesand coupling means being detachably secured to said shafts.

6. In a multi-frequency tuning system for covering various frequencyranges, a bank of groups of condenser units, each unit of a group ofunits including a gang of rotors and a gang of stators, one group ofunits tuning the same portion of the spectrum and a portion differentfrom that tuned by any of the other groups of units, an operating shaft,a shaft for each group of gangs of rotors, an outer shaft, said shaftsbeing disposed in ali ned relation and electrically insulated from eachother shaft, an insulated coupling means between said operating shaftand one of the shafts carrying a group of gangs of rotors, a switchingstructure for each group of condenser units and including an operatingmeans therefor, said structures including electrically insulatedrotatable means for coupling the others of said shafts and the operatingshaft together, the said coupling means and said shafts providing arotatable element common to the said groups of gangs of rotors, the saidgroups of gangs of rotors being angularly disposed with respect to andarranged in staggered relation about said element, the gangs of rotorstuning the same portion of the spectrum bearing the same angularrelation to each other, each higher or lower range tuning group ofcondenser units being disposed in staggered relation, said groups ofgangs of rotors being arranged about said rotatable element whereby whenthe latter is rotated 360 each group of gangs of rotors progress throughtheir associated gangs of stators in a direction which produces anincreasing or decreasing frequency range, the said coupling means ofeach of said structures carrying the operating means for the latter, thesaid operating means of said structures being so disposed about saidrotatable element in staggered spaced relation to each other andcorresponding in arrangement to the staggered spaced relation of saidgroups of gangs of rotors whereby on the rotation of said element theclosing of one switching structure will be had on the opening of anadjacent switching structure.

'7. In a multi-frequency tuning system as set forth in claim 6, having aselectively operable plural adjusting means for each switchingstructure.

8. In a multi-frequency tuning system as set forth in claim 6, havingmeans for adjustably connecting the coupling means forming a part ofeach of the switching structures to a pair of shafts.

9. In a multi-frequency tuning system as set forth in claim 6, havingthe said operating means for each of said structures consisting of apair of spaced parallel cams of like form.

10. In a multi-frequency tuning system for covering various frequencyranges, a bank of groups of condenser units, each unit of a group ofunits including a gang of rotors and a gang of stators, one group ofunits tuning the same portion of the spectrum and a portion differentfrom that tuned by any of the other groups of units, an operating shaft,a shaft for each group of gangs of rotors, an outer shaft, said shaftsbeing disposed in aligned relation and electrically insulated from eachother shaft, an insulated coupling means between said shafts carrying agroup of gangs of rotors, a switching structure for each group ofcondenser units, each structure including a rotatable section and asuspended section carrying spaced normally open circuit closing units,said suspended section being suspended from portions of a pair ofaligned shafts, said rotatable section coupling the said pair of alignedshafts together, said coupling means, rotatable sections and shaftsproviding a rotatable element common to the said groups of gangs ofrotors, the said groups of gangs of rotors being angularly disposed withrespect to and arranged in staggered relation about said element, thegangs of rotors tuning the same portion of the spectrum bearing the sameangular relation to each other, each higher or lower range tuning groupof condenser units being disposed in staggered relation, said groups ofgangs of rotors being arranged about said rotatable element whereby whenthe latter is rotated 360 each group of gangs of rotors progress throughsaid associated stators in a direction which produces an increasing ordecreasing frequency range, the rotatable section of each switchingstructure carrying the operating means for the group circuit closingunits of the structure, the said operating means for the circuit closingunits of said structures being so disposed about said rotatable elementin staggered spaced relation with respect to each other andcorresponding in arrangement to the staggered spaced relation of saidgroups of gangs of rotors whereby on the rotation of said element theclosing of one group of circuit closing units will be had on the openingof an adjacent group of circuit closing units.

11. In a multi-frequency tuning system as set forth in claim 10, havinga selectively operable plural adjusting means for each circuit closing 7unit of a switching structure.

12. In a multi-irequency tuning system as set forth in claim 6, having aselectively operable rotatable adjusting means for each of saidswitching structures.

13. In a mu tiple frequency tuning system, as set forth in claim 10,having means on the suspended section of each switching structurewhereby the circumferential adjustment of the latter may be had withrespect to its suspension means to prevent overlapping of the wavebands,

14. In a multiple frequency tuning system, as set forth in claim 10,having means forming a part of each switching structure coacting withthe suspension means for said structure to provide for the advance ordelay of the switching action for the gang of condenser units with whichit is associated whereby said structure will cut in and out of circuitthe said gang of condenser units at the point where the gang ofcondenser units next above or below take up.

15. In a multi-frequency tuning system, as set forth in claim 1, asupport for said rotatable means, and adjusting coactable means on saidrotatable means and on the suspension for each pair of circuit closingunits for detachably securing the suspension to the said rotatable meansto prevent overlap on tuning the dial between the several tuned bands.

16. In a multi-frequency tuning system, as set forth in claim 10, havinga rotatable adjusting means for each of said structures whereby thestructures may be set at points to prevent repetition or overlapping onthe tuning dial.

17. In a multi-frequency tuning system for covering various frequencyranges, a bank of groups of condenser units, each unit of a groupincluding ganged rotors and ganged stators, each associated with arotor, and each stator insulated from each other stator, one group ofunits tuning the same portion of the spectrum and a portion differentfrom that tuned by any of the other groups, a rotatable means common tothe gangs of rotors, said gangs of rotors being angularly disposed withrespect to and arranged in staggered relation about said means, thegangs of rotors tuning the same portion of the spectrum bearing the sameangular relation to each other, each higher or lower range tuning groupof units being disposed in a progressively staggered relation, saidgroups of gangs of rotors being so arranged about said rotatable meansthat when the latter is rotated 360 each group of gangs of rotorsprogress through their associated gangs of stators in a direction whichproduces an increasing or decreasing frequency range, a normally openpair of circuit closing units suspended from said rotatable means foreach group of condenser units and arranged adjacent to the latter, and arotatable operating device for each pair of circuit closing units, eachof said devices forming a part of said rotatable means and including apair of spaced elements for simultaneously closing the pair of circuitclosing units with which the device is associated, the said spacedelements of said devices being disposed about said rotatable means instaggered relation with respect to each other and corresponding inarrangements to the staggered arrangement of said groups of gangs ofrotors whereby on the operation of said rotatable means the closing ofone pair of circuit closing units will be had on the opening of anadjacent pair of circuit closing units.

18. In a multifrequency tuning system as set forth in claim 17, havingthe said rotatable means thereof consisting of a series of alignedshafts electrically insulated from each other shaft, a

coupling means between an intermediate pair of said shafts and thecircuit closing units operating devices, the said devices connecting theother of said shafts together and to the said intermediate shafts.

WEBSTER I. CARPENTER.

